Immune System Rejuvenation

Created on Dec. 21, 2012, 6:40 p.m. by Hevok
& updated by
Hevok
on May 2, 2013, 4:54 p.m.

There are several approaches to prevent the age-related changes of the Immune System, such as Thymus Rejuvenation, stem cells recovery, modulation of hormone production, and others. Specifically the approaches to the Immune System Rejuvenation are the following:

One of the first approaches tested was the old immunocompetent cells replacement by young ones.
For this, the immune response (PFC per splenocytes) and parameters (thymus weight, PHA-stimulated T-cell proliferation, CD4+44+ splenocytes) to SRBC (CD2; a cell adhesion molecule found on the surface of T cells and natural killer cells) in lethally irradiated heterochronic chimeras with syngeneic bone marrow cell repopulation in CBA/Ca mice was investigated. Young into old does not rejuvenate (in terms of parameters studied), but old into young does deteriorate [Bull. Exp. Biol. Med. -1996. - V.122, No. 9. - P.301-305].

Age-related changes in hematopoietic stem cell functions are not key for the significant immunological dysfunctions.

Hematopoietic stem cells transplantation is not effective for immune system rejuvenation.

Conclusions

The passive transfer of youth factors (such as young hematopoietic stem cells, lymphoid cells serum) to old animals is unable to rejuvenate old immune system.

The replacement of old lymphoid microenvironment by the young one may lead to partial recovery of immune function.

Old blood contains factors that can induce aging of a young organism.

The identification and elimination of these factors from the blood of old animals may be one of the approaches to lifespan extension.

The induction of senescent phenotypes in young heterochronic parabionts indicates that senescence is a result of developmental mechanism, that may accelerate ontogenesis